This invention relates to a light reflective material and a method of manufacture thereof. More particularly, this invention relates to a light reflective material manufactured by a transfer process wherein the final product comprises a laminate having the following layers: a protective coating preferably made from a lacquer material, a reflective material, a layer of adhesive and a layer of metal backing. Preferably, this invention also includes a second layer of a lacquer material between the reflective material and the adhesive layer.
Light reflective materials of the type contemplated by the present invention are well known and find many uses. Such materials typically include a reflective film usually made of silver which is adhesively fixed to a flexible metal backing. This material is then bent or formed (e.g., worked) to a suitable shape and then applied to a desired article of manufacture. Presently, two well known prior art light reflective materials are in use. The prior art materials are respectively shown in FIGS. 1 and 2.
Referring now to FIG. 1, a first type of prior art reflective material is shown generally at 10. Reflective material 10 includes a metal backing or substrate 12 having an adhesive coating 14 thereon. A layer of reflective material 16 (usually silver) is in adhesive contact with adhesive layer 14. The outer surface of reflective layer 16 includes polymeric film 18 which is usually a polyester film (PET). Finally, a removable protective layer 20 of polymeric film is typically applied to the top surface of polyester film layer 18. After assembling layers 12, 14, 16, 18 and 20, the stack-up 10 is laminated. The light reflective material 10 of FIG. 1 is then bent or formed to a desired shape and applied to a desired article. Thereafter, the removable protective layer 20 is removed so that the final product comprises an outer layer of polymeric film 18 along with the inner layers of reflective material 16, adhesive 14 and metal substrate 12.
The prior art reflective laminate of FIG. 1 suffers from certain known deficiencies and drawbacks. For example, the outer polymeric film 18 impairs reflectivity. In addition, film layer 18 may also tend to delaminate. Also, another drawback is that at certain bend sites, film 18 will craze with time which also impairs the reflectivity of the material. Still another deficiency of the FIG. 1 prior material is that along cut edges of the laminate, the film may separate at local sites. These separated local sites may then act as sites for corrosion of the reflective metal 16.
FIG. 2 presents a second known prior reflective material 22 which has certain advantages over the prior art material of FIG. 1; but still continues to suffer from certain drawbacks which will be discussed below. The laminate 22 of FIG. 2 comprises a metal backing or a substrate layer 24 having a layer of suitable adhesive 26 thereon. In contrast to the material of FIG. 1, a layer of polymeric film 28 (usually polyester film) is then adhered to adhesive layer 26. Next, reflective material 30 (typically silver) is provided onto plastic film layer 28. Finally, a thin protective coating 32 is provided on reflective material layer 30. Protective coating 32 is typically comprised of a hard resin such as acrylic. As in the FIG. 1 prior art laminate, a removable protective layer 34 is provided onto protective coating 32. The stack-up is laminated. Removable layer 34 protects the laminate against scratches and marring when the reflective laminate 22 is being formed; and is then removed subsequent to such working.
The prior art material of FIG. 2 has an important advantage over the prior art material of FIG. 1 in that the loss of reflectivity caused by the presence of the polyester film 18 in FIG. 1 is reduced since said polyester film is provided on the underside of reflective layer 30 in FIG. 2. However, prior art FIG. 2 still necessitates the use of a removable protective layer 34 for protecting the reflective material during working. The use of this separate peel off protective film adds to the materials and labor costs during manufacture. In addition, other disadvantages of the prior art material of FIG. 2 are that since the reflective material 30 is added onto the film 28 (rather than onto protective coating 32) the protective coating 32 will tend to flake off the layer of reflective material. In addition, the presence of the polyester film 28 adds significantly to the overall thickness of the material. Finally, like the FIG. 1 embodiments, the presence of film 28 can eventually lead to cracking, crazing and like problems.
It will be appreciated that in both FIGS. 1 and 2, the reflective materials 16 and 30 are deposited on PET films 18 and 28 respectively by well known metal deposition techniques. Thereafter, all of the layers shown are laminated in a conventional manner.